Many people with sickle cell disease (SCO) or sickle cell trait (SCT) lack sufficient reproductive health knowledge about the genetic transmission of the condition to their children. We propose a two-phase study of adult men and women, aged 18 to 35 years, with SCD or SCT, and recruited from SCD clinical care or community sites in Chicago. One phase is formative and the other is a longitudinal, randomized controlled trial to compare the effects of usual care or usual care plus CHOICES on reproductive health knowledge, intentions, and behaviors. The CHOICES intervention is an Internet-based, tailored, multimedia education program about reproductive options and consequences, and is designed to help men and women with SCD or SCT to implement a parenting plan that will support their informed reproductive health decisions and reproductive health behaviors. In phase 1. we will conduct think aloud interviews with a group of 50 adults as they review the CHOICES intervention and study instruments and readminister study tools 3-4 weeks afterward to assess reliability. Using findings from phase 1, we will refine the CHOICES intervention and instruments. We expect that the think aloud interviews will support the feasibility and cultural appropriateness of the CHOICES intervention and validity of the instruments and retest will support reliability. In phase 2. we will conduct a 2-year, randomized, repeated measures trial in 200 adults (half with SCD, half with SCT) to: compare immediate effects of usual care or usual care plus CHOICES on SC reproductive health knowledge, informed reproductive health decisions, and intention to implement a parenting plan; 2) determine the sustained effects on SC reproductive health know-ledge and Informed reproductive health decisions (at 6 &12 months) and reproductive health behaviors (at 6,12,18, &24 months). At 6 &12 months, we will provide the CHOICES group with a booster of the CHOICES education tailored to their knowledge deficits at posttest and at 6 and 12 months;and 3) describe changes in personal factors and subjective norms, and other demographic factors related to reproductive health intentions and behavior during the two-year study. We hypothesize that immediate (posttest) and sustained (6 &12 months) SC knowledge scores and informed decisions scores will be greater in the CHOICES than usual care groups;a larger proportion of the CHOICES group than usual care group (a) will report intention to implement a parenting plan (at posttest, 6 &12 months);and (b) have reproductive health behaviors consistent with the parenting plan (at 6,12,18, &24 months). We also expect to describe changes in personal and subjective norm factors over the 2 year study period in the CHOICES and usual care groups. Ultimately we will be well positioned to lead a Nationwide, multicenter study translating CHOICES into routine clinical care of SCD patients, which would provide the sorely needed education about the genetic transmission of SCD and SCT.